Pulp press



March 31, 1964 M KOELSCH 3,126,818

PULP PRESS Filed Jan. 24, 1963 3 Sheets-Sheet 1 March 31, 1964 M. KOELSCH PULP PRESS 3 Sheet s-Sheet 2 Filed Jan. 24, 1963 OOOQOOO 00C 0000 D 00000 00000 000000 0 0 I 0 d 0 0 0 I 0 I0 n 0 O 0 0 L l 0 0 0 I 0 March 31, 1964 M. KOELSCH 3,126,818

PULP PRESS Filed Jan. 24, 1965 3 Sheets-Sheet 3 United States Patent Ofiice 3,126,818 Patented Mar. 31, 1964 3,126,818 PULP PRESS Lester M. Koelsch, Beloit, Wis, assignor to Beloit Corporation, a corporation of Wisconsin Filed Jan. 24, 1963, Ser. No. 253,579 8 Claims. (Cl. ltltlll2) This invention relates to extraction devices and more particularly to continuous pulp presses for extracting and expressing liquids from liquid containing stock.

Conventional pulp presses generally comprise, as disclosed in US. Letters Patents No. 1,354,528, No. 2,664,- 814 and No. 2,709,957, a cylindrical perforated shell surrounding a co-axially disposed rotating conical tapered spindle provided with a helical flight arrangement with the divergent end of the spindle disposed at the discharge end of the press. In operation of the presses, the liquid containing material treated is continuously compressed in its travel to the discharge end of the press in order to express the maximum amount of liquid from the stock material. In operation of these presses it was found that regardless of the amount of compression effected by the extrusion screw a certain unattainable quantity of liquid was retained in the stock material. It was also found that further extraction of liquid, from the material, was drastically reduced and/or for all practical purposes stopped after the material was compressed to an optimum radial thickness in a dimension measured radially across the extrusion area or gap defined between the shell and spindle. In consequence it was thus discovered that the continuing expression of liquid is dependent on maintaining uninterrupted radial channels of flow for the liquid between particles of solid material of the stock, from which the liquid was being expressed, and conversely a continuous reduction in thickness of the material under axial and radial compression constrained the solid particles to form closed cells with increasing resistance to flow, entrapment of liquid therein and obstruction flow of the liquid from similar adjacent closed cells.

It was thus discovered that increased extraction of fluid from various materials could be obtained by maintaining an optimum radial thickness of the material and thus provide continuing radial channels of flow or drain from the expressed liquid over a portion of the axial travel of the stock material through the pulp press. Generally speaking this is accomplished by a modification in the spindle configuration so as to provide on the opposed and adjacent portions of the spindle and shell which are adjacent the discharge end of the press, surface areas which extend in parallel relationship with each other.

In addition, in operation of these pulp presses, portions of the material to be extracted lodge on the screen and accumulate and build up as a coating or layer thereon forming a liquid flow barrier, on the screen, between the gap formed between the screen and the periphery of the helical threads to bind the screen and thus interfere with further extraction of liquid from the material. Heretofore, removal of such accumulations required disassembly of the press with the attendant down time for cleaning with consequent interruption of production and efficiency of the extraction operation. It has been discovered that such accumulation of the material can be substantially reduced by swingably mounting at the periphery of the helical threads, of the spindle, screen wiper blades adapted to be yieldably actuated against the screen and thereby in their traversal passing across the screen clear the accumulating material therefrom by forced removal, shearing and the like.

It is accordingly an object of this invention to provide a novel pulp press of increased efliciency.

It is another object of this invention to provide a novel pulp press designed for increased extraction of liquid from liquid containing stock materials.

A further object of this invention is to provide a pulp press having novel means for maintaining the screen thereof free from the accumulation of solid material thereon.

Other objects and advantages will become more apparent from the following description and drawings in which:

FIGURE 1 is an elevational, partly in section, view illustrating an embodiment of this invention;

FIGURE 2 is a partial sectional view taken along line II-II of FIGURE 1;

FIGURE 3 is an elevational view of the spindle assembly shown in the preceding figures;

FIGURE 4 is a side view of the assembly shown in FIGURE 3;

FIGURES 5 to 7 depict three views of the wiper blades employed in the spindle assembly of the preceding figures;

FIGURE 8 is a plan view illustrating a modification of a wiper blade adapted for use in the spindle assembly of the preceding embodiment;

FIGURE 9 is an elevational view illustrating another embodiment of this invention; and

FIGURE 10 is a partial sectional view taken along line XX of FIGURE 9.

Referring to the drawings shown therein, is a pulp press similar to the construction of the aforesaid patents, and comprised of a frame plate I mounted on a conventional support structure such as I-beams 2 suitably disposed in concentric spaced relationship about the plate, which includes a bearing collar 3 having journaled therein the upper or neck portion 4 of a conical tapered extrusion spindle 5 internally disposed within a perforated cylindrical shell 6 suitably mounted at its upper end to the frame plate in depending relation therefrom. As will be understood, in accordance with conventional practices, the shell is perforated to facilitate the passage of ex pressed liquid therethrough during extrusion of stock in the press on passage therethrough; and the shell may form a screen for retaining material during extraction and expression of liquid from various substances, as food pulp and the like, or the shell may form a backing or perforate structural support for the mounting on its wall surfaces of a secondary screen 7 of desired mesh.

Surrounding the perforate shell 6 and depending in suitable securement from frame plate 1 is a cylindrical imperforate housing or casing 8 in coextension with the shell. Secured to the lower portion of the shell 6 and the housing 8 is a trough 9 defined by a conical annular wall plate 10 and a cylindrical wall portion 11 suitably secured together and to the shell 6 and the housing 8. As will be appreciated the trough 11 may take any configuration, and if desired the walls thereof may form integral extensions of the shell 6 and/ or the housing 8. Depending from the trough 11 is a suitable skirt 40 for confiining the discharge end of the press.

Rotatably mounted in spaced relationship within the shell 6 is the spindle 5 thus forming therebetween an extrusion chamber 11. The spindle 5 is supported in shell 6 by means of depending extension 12 rotatably journaled in a hydraulic chamber 14 of a hydraulic support 13, adapting the spindle for vertical adjustable and controlled movement by means of a desired variation of and control of pressures delivered to hydraulic chamber 14 through an inlet 15. As illustrated in this embodiment, the spindle is of conical or tapered configuration having its divergent end 16 disposed adjacent the discharge end of the press thus forming a progressively constricted area in the extrusion chamber toward the dis-- charge end of the press. Fixedly mounted along the spindle 5 is a continuous, or if desired interrupted, helical or spiral flight arrangement 17 having in the embodiment illustrated uninterrupted threads or screw element extending radially into close proximity with the inner wall of shell 6. The provision of the flight arrangement 1'7 adapts the spindle for effecting movement of stock in the extrusion chamber toward the discharge end 16 of the press on rotation of the spindle actuated by conventional motor means, not shown, suitably connected or geared to the neck portion 4 of the spindle.

Accordingly, on rotation of the spindle, the threads of the flight arrangement 17 engage the stock fed into the extrusion chamber 11 and force the stock material downward toward the discharge end of the press through the progressively constructed annular area defined between the spindle 5 and shell 6. Discharge of the material from the press is controlled by means of a choke cone mounted at lower portion of spindle 5 in cooperating relationship with the conical wall of trough 11. The feed or fiow of the liquid containing material into the extrusion chamber is accomplished by means of an inlet conduit 18 extending into the extrusion chamber through housing 8 and shell 6, with removal of the fluid passing through the shell and collecting in the trough 11 effected by means of a discharge line 19 connected into the trough.

To eliminate and prevent binding of the shell due to lodging and accumulation of solid material thereon, a plurality of screen wiper blades 2% are mounted in helical spaced relationship to each other along the threads or flight elements 17 adjacent the periphery thereof. Each of the wiper blades is of elongated configuration for longitudinal extension along the inner wall of the shell. The Wiper blades are adapted for swinging movement on the thread or flight elements by means of a bifurcated projection forming lugs 21 for receiving the flight element therebetween to which the wiper blade is pivotally mounted by means of a pin 22 extending through the lug holes 23 and mounting hole 24 provided in the flight element. Since the wiper blade is freely pivotable it is thus adapted for swinging movement against the shell 6. Preferably to provide for optimum clearance between the spindle assembly and the shell the flight elements may be suitably notched at 25 to accommodate retraction of the wiper blades therein. The wiper blades of this embodiment have been designed for self-loading by forming thereon a loading face or surface 26 disposed in opposition to the rotation of the spindle. These loading faces are designed to have an extension 27 defining both an angle a with the radius 28 of the shell and an angle b with a tangent 29 of the shell therein thus forming an acute angle with the portions of the shell inner Wall traversed by the loading face. In this manner the selfloading wiper blade is actuated by the stock which forces the blade against the shell, thereby cleaning the shell of material and preventing accumulation of the material thereon by removing and shearing the particles lodging or depositing on the shell. However, it is to be understood, that although the wiper blades of this embodiment have been illustrated as self loading, these wiper blades are readily adaptable for spring, pneumatic and hydraulic loading to force or urge the wipers against the shell. Also as will be appreciated the wipers may be constructed of any material compatible with the stock being processed in the press, and accordingly may be made of metal, synthetic material or a combination of metal and plastic as desired or required for any specific application. In addition it is to be understood that although the wiping blades of this invention have been described in specific application to the pulp press described, the wiper blades of this invention are readily applicable for use with other like devices employed for de-watering or extracting liquid from various types of liquid containing stock.

FIGURE 8 illustrates another embodiment of the wiper blades of this invention in which the modified blades 41 d trail the rotation of the thread elements 1'7, in rotation in constrast to leading characteristic of the previous embodiment. In addition, this wiper modification is provided with an arcuate loading face 39 in contrast with the planar face 25 of the previous embodiment.

FEGURE 9 illustrates another embodiment of this invention incorporating a press spindle 31 of hollow construction with the peripheral surface thereof optionally perforated to facilitate flow of expressed fluid therein for collection and removal through a discharge conduit 32. Movement of the spindle for choke control is accomplished by means of hydraulic or pneumatic cylinders 33 concentrically mounted to and about the spindle. To resist the rotation of the stock in the extrusion chamber the shell is provided with a plurality of projections or bars 37 which project internally therefrom in to the extrusion chamber intermediate a plurality of interrupted spiral flights 34 fixedly mounted in helical arrangement along the spindle.

Also as illustrated in this embodiment, the press is adapted for increased extraction of liquid from the stock by forming the spindle with an upper portion 35 and a lower portion 36. The upper portion is provided with a tapered conical configuration having the convergent end thereof disposed adjacent the inlet of the press with its peripheral surface longitudinally defining a downwardly converging angle with the inner wall of the shell. The lower portion 35 is provided with configuration having a peripheral surface extending longitudinally parallel with the shell to form a uniform annular extrusion chamber of substantial length. This parallel relationship between the shell and the lower spindle portion prevents further radial compression of the extruded stock to maintain the material at optimum thickness to keep the radial drain channels therein open for continuing flow or" expressed fluid therethrough. As will be appreciated each particular stock under compression will have an optimum and maximum radial thickness peculiar to it, and accordingly the specific gap or spacing between the shell and the lower spindle portion forming the lower extrusion area, must necessarily be determined and employed for each particular stock treated.

Although the invention has been described with reference to specific materials, embodiments and details, various modifications and changes, within the scope of this invention, will be apparent to one skilled in the art and are contemplated to be embraced within the invention.

What is claimed is:

1. A pulp press comprising a perforated shell having an inlet adjacent one end thereof and a discharge end adjacent the opposite end thereof, a spindle co-axially mounted in spaced relationship with said shell and comprised of a first spindle portion and a second spindle portion, said first spindle portion being of tapered conical configuration having the convergent end thereof disposed adjacent the said inlet of said press with the peripheral surface of said first spindle portion longitudinally defining an angle with the inner wall of said shell, said second spindle portion forming a continuation of said first spindle portion from the divergent end thereof and having a peripheral surface extending longitudinally parallel with the said inner wall of said shell toward the said discharge end of said press, a helical flight arrangement fixedly mounted along said first and second portions of said spindle with the threads of said flight arrangement extending radially into close proximity with said inner wall of said shell a plurality of wiper blades swingably mounted on the said threads of said flight arrangement adjacent the periphery thereof, each of said blades being elongated in longitudinal extension along said inner wall and adapted for swinging move ment into yieldable contact with said inner wall for removal of material lodged on said inner wall, motor means for effecting relative rotary movement between said spindle and said shell to move material toward the said discharge end of said press, and liquid gathering means disposed externally of said shell for collecting liquid passing through said shell externally thereof.

2. The structure of claim 1 wherein each of said blades is self-loading and comprises a loading surface disposed in opposition to said rotary movement and having an extension defining an angle with the radius of said shell and with a tangent of said inner wall thereat, said blade surface forming an acute angle with the surface of said inner wall traversed thereby.

3. A pulp press comprising a perforated cylindrical shell having an inlet adjacent one end thereof and a discharge end adjacent the opposite end thereof, a spindle co-axially mounted in spaced relationship with said shell and comprised of a first spindle portion and a second spindle portion, said first spindle portion being of tapered conical configuration having the convergent end thereof disposed adjacent the said inlet of said press with the peripheral surface of said first spindle portion longitudinally defining an angle with the inner wall of said shell, said second spindle portion forming a continuation of said first spindle portion from the divergent end thereof and having a peripheral surface extending longitudinally parallel with the said inner wall of said shell toward the said discharge end of said press, a helical flight arrangement fixedly mounted along said first and second portions of said spindle with the threads of said flight arrangement extending radially into close proximity with said inner wall of said shell, a plurality of wiper blades swingably mounted on said threads of said flight arrangement adjacent the periphery thereof, each of said blades being elongated in longitudinal extension along said inner wall and adapted for swinging movement into yieldable contact with said inner wall for removal of material lodged on said inner Wall, motor means for imparting rotary movement to said spindle relative to said shell to move material toward the said discharge end of said press, and liquid gathering means disposed externally of said shell for collecting liquid passing through said shell externally therethrough.

4. The structure of claim 3 wherein each of said blades is self-loading and comprises a loading surface disposed in opposition to said rotary movement and having an extension defining an angle with the radius of said shell and with a tangent of said inner wall thereat, said blade surface forming an acute angle with the surface of said inner wall traversed thereby.

5. A pulp press comprising a perforated shell, having an inlet adjacent one end thereof and a discharge end adjacent the opposite end thereof, a conically tapered spindle co-axially mounted in spaced relationship within said shell and having the convergent end thereof disposed adjacent the said inlet of said press with the peripheral surface of said spindle longitudinally defining an angle with the inner wall of said shell, a helical flight arrangement fixedly mounted along said spindle with the threads of said flight arrangement extending radially into close proximity with said inner wall of said shell, a plurality of Wiper blades swingably mounted on the said threads of said flight arrangement adjacent the periphery thereof, each of said blades being elongated in longitudinal extension along said inner wall and adapted for swinging movement into yieldable contact with said inner Wall for removal of material lodged on said inner wall, motor means for effecting relative rotary movement between said spindle and said shell to move material toward the said discharge end of said press, and liquid gathering means disposed externally of said shell for collecting liquid pasing through said shell externally thereof.

6. The structure of claim 5 wherein said shell is cylindrical and said motor means imparts rotary movement to said spindle relative to said shell.

7. The structure of claim 5 wherein each of said blades is self-loading and comprises a loading surface disposed in opposition to said rotary movement and having an extension defining an angle with the radius of said shell and with a tangent of said inner Wall thereat, said blade surface forming an acute angle with the surface of said inner wall traversed thereby.

8. The structure of claim 7 wherein said shell is cylindrical and said motor means imparts rotary movement to said spindle relative to said shell.

References Cited in the file of this patent UNITED STATES PATENTS 1,354,528 Wertenbruch Oct. 5, 1920 1,521,044 Parker Dec. 30, 1924 2,181,404 Koppitz et al. Nov. 28, 1932 2,491,852 Carvel Dec. 20, 1949 2,664,814 Ahlborn Jan. 5, 1954 2,709,957 Armstrong June 7, 1955 2,903,960 Zies Sept. 15, 1959 FOREIGN PATENTS 560,184 Germ-any Sept. 29, 1932 

5. A PULP PRESS COMPRISING A PERFORATED SHELL, HAVING AN INLET ADJACENTONE END THEROF AND A DISCHARGE END ADJACENT THE OPPOSITE END THEREOF, A CONICALLY TAPERED SPINDLE CO-AXIALLY MOUNTED IN SPACED RELATIONSHIP WITHIN SAID SHELL AND HAVING THE CONVERGENT END THEREOF DISPOSED ADJACENT THE SAID INLET OF SAID PRESS WITH THE PERIPHERAL SURFACE OF SAID SPINDLE LONGITUDINALLY DEFINING AN ANGLE WITH THE INNER WALL OF SAID SHELL, A HELICAL FLIGHT ARRANGEMENT FIXEDLY MOUNTED ALONG SAID SPINDLE WITH THE THREADS OF SAID FLIGHT ARRANGEMENT EXTENDING RADIALLY INTO CLOSE PROXIMITY WITH SAID INNER WALL OF SAID SHELL, A PLURALITY OF WIPER BLADES SWINGABLY MOUNTED ON THE SAID THREADS 